There was once a hippoIpotamus who was a mathematical genius. He could do any calculation in his head, and he always got the right answer.
One day, he was lying in his mudhole, humming to himself and working out Pi to 300 decimal places using the Fibonacci series, when he felt a terrible pain behind the eyes. ‘It must be all this calculating that is giving me such a headache,’ he thought, ‘I really ought to go and have my eyes tested.
To tell you the truth, the hippo was very, very short-sighted but he refused to admit it, even to himself. The optician gave him a strong pair of glasses, and said (because he did not want to hurt the hippo’s feelings): ‘You don’t need to wear them all the time, but I think you should wear your glasses whenever you feel like doing any sums in your head.’
The hippo caught sight of himself in the mirror, and thought: how intelligent he looked in glasses, so he kept them on, stopping to admire his reflection in every pool as he walked back to his mudhole.
On the way, he caught sight of a notice nailed to a tree. Thanks to his wonderful new glasses, he could also make out what was written on it. It said, quite simply: 2 + 2 = 5.
The hippo looked up at the notice board once again. 2+ 2 = 5? He scratched his head (not an easy thing for a hippopotamus to do) and began to mutter to himself: ‘That can’t be right. There must be some mistake.’ He sat down (which can also be a problem for a hippo) and tried to work out for himself how 2+ 2 could be made to equal 5.
He thought too about the person who had written the expression up on the board. Somebody had written it, and they must have had a good reason for doing so. There must be something in it.
Finally, he got very angry, tore the notice down, and took it back home with him. He put it on the ground and continued to stare at it for days on end, no longer bothering to eat or drink, or even to roll in his beautiful mudhole. 2+2=5.
He took off his new glasses to wipe off same mud. Immediately the board and the crazy expression became a blur – he could no longer see the figures 2 or 5; nor could he make out the plus or the equal signs.
Suddenly, he began to feel much better, as if a big weight had been lifted off his shoulders. He smiled (which is a VERY difficult thing for a hippo to do), rolled over in the mud, and began to sing. He no longer had a problem, and the world looked beautiful again. After that, he gave up maths and took up singing instead.
Moral: If you want to see things really clearly, take your glasses off.